1. Field of the Invention:
This invention relates to a skiving cutter device for use in cutting an internal spur gear.
2. Description of the Prior Art:
In usual gear skiving processes for manufacturing an internal spur gear, a skiving cutter having cutter blades, each formed in the shape of a gear tooth along a staggered axis, has been used as a fly cutter rotated within a vacant space for skiving or cutting a work piece to be cut to form an internal spur gear.
This working process is highly efficient as compared with other usual cutting processes. However, since it has inevitably caused the staggered contact between the cutter and the work piece to be cut, analyzing design procedures thereof has been troublesome. Therefore, the analysis thereof was insufficient and unsatisfactory. For this reason, in order to effect, in turn, rough skiving and finish skiving, it has been necessary to interchangingly mount on a spindle of the cutter device a cutter selected from at least two cutters different from each other, that is, one is used for rough skiving and the other is used for finish skiving, thereby lowering the working efficiency in this respect.
Lately, such a gear skiving process has been theoretically analyzed at last. As a result, an interference diagram (which is described afterwards in detail) has been obtained on several theoretically ananlyzed values. By the diagram, it has been understood that a contacting or acting region between each cutter blade of the skiving cutter and each gear tooth of an internal spur gear to be obtained by skiving or cutting a work piece with the cutter is the portion on the diagram encompassed by respective interference lines at the root and bottom of the tooth formed on the work piece to be skived or cut and an interference line at the addendum of each blade of the cutter. Therefore, it has been understood that if each blade profile of the skiving cutter is designed such that the contacting point between each cutter blade of the skiving cutter and each gear tooth of an internal spur gear to be obtained by skiving or cutting a work piece is located within the contacting or acting region, a plurality of cutter gears can be mounted on the same spindle because the cutters can be set thereon in a predetermined vertical alignment.
This invention has been made in consideration of the above described view point.